Calculation of Imbibition Relative Permeability for Two- and Three-Phase Flow From Rock Properties

TLDR: In this paper, a relation between residual nonwetting-phase saturations and initial non-wetting pbase saturations is derived from published data, which is used in conrzection with established theory relating re?at ive permeabiiit y to pore-size distribution.

Abstract: Relative permeability /urrctiovs are developed {or both twoarrdthrec.phase systems with tfie satr.:ation changes in the imbibition direction. An empiricul relation between residual nonwetting-phase safura. tion ajter water imbibition and initial nonwetting pbase saturations is /ound from pu.blishcd data. Fro7n this empirical relation, expressions are obtained /or trapped and mobile nonwetting-pb(~.se saturations which are used in conrzection with established theory relating re?at ive permeabiiit y to pore-size distribution. Tbe resulting equations yield relative permeability as a /unction o/ saturation having characteristics beiieved to be representative of real systems, Tbe relative permeability o/ water wet rocks for both twoand three pbuse systems, with the saturation cba,nge in the irnbibit ion direction, may be obtained by tijis method after properly selecting two rock properties: the residual nonwe tt ing-phase sat urvrtion aiter tbe complete imbibition cycle, and the cap illary pressure curve.